[google-appengine] One-to-many relation problem

[Bat]

Hi All,

I'm trying to use the one-to-many relation with heritance but without
success. Let me explain.

I have 3 classes :

@PersistenceCapable
@Inheritance(strategy = InheritanceStrategy.SUBCLASS_TABLE)
    public abstract class Op {
    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    public Key key;

    @Persistent(mappedBy = "op")
    @Element(dependent = "true")
    private ArrayList<Entry> entryArr = new ArrayList<Entry>();
}

 @PersistenceCapable
public class ExtendedOp extends Op {
    public double quota;
}

@PersistenceCapable
public class Entry {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
public Key key;

@Persistent
    private Op op = null;
}

When I persist, I use this code :
ExtendedOp op = new ExtendedOp();
op.addNewEntry(new Entry());
op.addNewEntry(new Entry());
pm.makePersistent(op);

After, I persisted, I reload the "ExtendedOp" with this :
String connectionQuery = "select from " + ExtendedOp.class.getName();
 opArr = (List<ExtendedOp>) pm.newQuery(connectionQuery).execute();
     if (opArr != null) {
                for (ExtendedOp opExt : opArr) {
                    if ( opExt.getEntryArr() != null)
                        for (Entry entry : sale.getEntryArr()) {
                            System.out.println("ok"); //works!
                            if (entry.getOp() != null)
                                System.out.println("perfect"); //never
display
                        }
                }
            }

The problem is : the Entry has the field "operation" always null. This
field is from the relation one-to-many. Maybe this field is still null
because is class type is "parent" of ExtendedOp?

Could you help me to solve that problem?

Thanks you very much,

Bat

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